Chinese companies are reportedly the actual operators of the vessels that entered South Korean ports with North Korean coal shipments last year.

The Voice of America(VOA) reported on Wednesday that the vessels' operators were companies based in China, citing the records of Port State Control in the Asia-Pacific Region.

According to the report, the operator of the Panamanian-flagged Sky Angel, which entered South Korea's Incheon Port on October second last year, was registered as Dalian Sky Ocean International Shipping Agency with its address in Dalian in China's Liaoning Province.

The operator of the Sierra Leonean-flagged Rich Glory, which entered Pohang Port on October eleventh last year, was registered as Sanhe Marine, also based in Dalian.

The VOA said that although the ships are operating under the flags of another country, the Chinese companies are the actual operators.